In a typical Internet protocol multimedia subsystem (IMS) network, each user device must register with the IMS network to receive services. Upon initial registration with the IMS network, a user device is assigned to a particular serving call session control function (S-CSCF), which will act as a call server for the user device. Additionally, a secured bound is established between the user device and the assigned S-CSCF. In a conventional IMS network, the established bound between the user device and the assigned S-CSCF will not change provided that the user device continues to re-register with the IMS network at appropriate intervals. As such, conventional IMS networks exhibit a fairly static allocation of user devices to particular S-CSCFs.